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Location:
Adelaide
Registered:
July 2002
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 03:28
 
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Could be knock sensor retarding timing.
It supposedly happens A LOT on GZE's with factory ecu.
ECU thinks it senses knocking, so retards timing.
Infact its just engine noise.
The SC14 is probably just makeing it noisier.
Could be a good time to upgrade to a standalone ecu.
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 03:36
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Nah, its not timing. It actually stops making boost. Somehow it stops boost production. I thought it was not possible to make anything other than full boost at any stage but I regularly see 6-8psi being made. It holds it steady too. The magnetic clutch still works great so there is something else there I have not allowed for. I don't have the bypass valve fitted any more (space constraints due to the longer supercharger) but I will fit one again when I get the time. I damaged it so if anyone has one they are willing to part with I would love to buy it. In hindsight, I should have just welded up the pulley. Is there any way to engage the magnetic clutch on a permenant basis?
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 03:38
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Only by giving it 12v all the time (or earthing it all the time, I'm not sure which way it works)
But if you pull enough timing out, boost will be reduced.
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Location:
Toronto, Downtown
Registered:
September 2004
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 04:47
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could also be a boost leak split pipe hold in i/c
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 04:53
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I thought about that too. I am using some serious clamps on the outlet side of the supercharger and it doesn't look or sound like I have a leaky intercooler. I still have the factory top mount which doesn't do squat really so I am in the process of water/air as we speak. I thought there may be issues with inlet temps. Is there any temp or pressure sensing done in the inlet tract, post supercharger?
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Location:
Toronto, Downtown
Registered:
September 2004
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 05:02
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i would imagine that a bigger floeing s/c would create less heat at the same boost pressures as the sc12
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Registered:
May 2002
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 05:03
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Possibry an intermitant sripping belt?
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there any temp or pressure sensing done in the inlet tract, post supercharger
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Quite certain there is, if your setup retains the standard hardware then I think it is sticking out of that pipe on top of the throttle body (very vague recollection)
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 05:13
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Belt is as tight as I dare. If the charge temp is any cooler than the SC12 it would be marginal. If anything, it seems hotter. Well over 100deg anyway and maybe over 200.
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Registered:
May 2002
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 05:31
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Belt is as tight as I dare.
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Is it a new belt?? Sometimes an older belt can harden a little and lose some grip. If it's tight and not 1000000km old then cross that off the list.
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If anything, it seems hotter. Well over 100deg anyway and maybe over 200.
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Seems like awfully high inlet temps
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Location:
Toronto, Downtown
Registered:
September 2004
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 05:50
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agree even 80 deg inlet temps would seriously worry me youd want something as close to ambient as possible
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Registered:
June 2005
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 06:49
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the relay that controls the sc clutch switces the negative. 99% sure about that, did a lot of fault finding on mine. thats how i got my ke20 4agze for $1000. Bought it running down on power, replaced a $7 relay, problem solved. saved heaps.
if your intake pipes are to hot to touch, like your saying '100 to 200 degrees', you have a bit of a problem i think.
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 08:00
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Try touching your own outlet snout after a drive. You will soon find out that yours is probably the same. That is the major drawback with a roots type sc. That is why you have an intercooler. I am running the bigger supercharger on a Nevo pulley so you can see why it is getting hot. Thanks though for the tip on the -ve clutch setup. As for the belt, it is new and correctly tensioned. It is not the belt. Can anyone out there tell me how a supercharger can run partial boost??? There is no wastegate to vent off boost and the clutch can't modulate on and off quick enough to give consistant partial boost. I am stumped.
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Registered:
June 2005
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 08:51
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id try engaging the sc clutch full time, at least you'll be able to rule out the computer switching it on and off. cant hurt. i might have i by-pass valve in a few weeks, ill let you know when i get it out. i'll pm you to see if you still need it.
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 12:52
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Thanks Muzza.
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Location:
Toronto, Downtown
Registered:
September 2004
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Re: Boost issues with 4AGZE
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Thu, 23 June 2005 14:25
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| Irish wrote on Thu, 23 June 2005 18:00 |
Try touching your own outlet snout after a drive. You will soon find out that yours is probably the same. That is the major drawback with a roots type sc. That is why you have an intercooler. I am running the bigger supercharger on a Nevo pulley so you can see why it is getting hot. Thanks though for the tip on the -ve clutch setup. As for the belt, it is new and correctly tensioned. It is not the belt. Can anyone out there tell me how a supercharger can run partial boost??? There is no wastegate to vent off boost and the clutch can't modulate on and off quick enough to give consistant partial boost. I am stumped.
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ahh mines allways hot but my inlet temps are nowhere near 200 deg they may be about 40-60 degs... thats why you have an i/c maybee outlet temps of the s/c are close to 100 deg but not inlet temps
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Location:
Adelaide
Registered:
July 2002
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Registered:
May 2002
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Location:
Perth WA
Registered:
December 2003
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Re: Boost issues with 4AGZE
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Fri, 24 June 2005 04:44
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Irish: i am in the same situation with EXACTLY the same problem, dies off in ay gear at any time, or hold boost till redline or dies off or doesnt make any boost.
the guy who suggested the knock sensor might be onto something..
ive been through it all, swapped back to piping of different types, taken the cooler out,s/c in and out, bypassed the s/c relay, ive even got the clutch tack welded so its on constant at the moment. tried different throttle bodies, different vacum setup etc etc
i have SAFCII and a boost gauge, sometimes i get 0.9 bar and it goes strong, i thought it was a leaking pipe until i had my SAFCII hooked up correctly now i can see that when it dies off or doesnt make boost the airflow percentage (flap open %) either goes down or doesnt go over 34% or thereabouts , which means its not actually physically drawing any air to make boost as the intake and boost pressure are relative.
i was planning on going and buying another sc14 today and putting that in, as ive been fairly convinced that its a mechanical fault in the s/c itself but after reading this im not so sure that two could fail identically as the theories i have are that a gear or something is loose and its simply not turning , as its a direct driven mechanical device and thats the only mechanical explaination that it would not suck in air to make boost, unless there is a leak in piping or compression. both i am sceptical can be on/off occurences.
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Location:
Bundaberg, Qld.
Registered:
May 2002
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Re: Boost issues with 4AGZE
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Fri, 24 June 2005 12:45
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i cannot see how the knock sensor could have anything to do with it, knock sensor will retard the timing if/when it hears knocking/pinging, but i cannot see how it could stop the s/c from producing boost.
the MAP gze electronics has a temp sensor doesnt it? what happens when that sensor see's over the set air temps? could it be shutting off the s/c via the ECU?
does the sc14 use the ACV?
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I don't have the bypass valve fitted any more (space constraints due to the longer supercharger) but I will fit one again when I get the time.
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i wouldnt bother, IMO the ABV is not needed when you are running the factory ECU and clutch set-up.
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the relay that controls the sc clutch switces the negative.
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indeed.
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Location:
Perth WA
Registered:
December 2003
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Re: Boost issues with 4AGZE
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Fri, 24 June 2005 13:41
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my s/c clutch has a welded clutch ( small tack weld ) so engaging/disengaging controls arent an issue.
i bought another sc14 today hoping that its the issue,something internal of the unit. will advise once installed on how it goes..
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Location:
Bundaberg, Qld.
Registered:
May 2002
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Location:
Perth WA
Registered:
December 2003
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Re: Boost issues with 4AGZE
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Wed, 29 June 2005 07:51
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my ABV has been removed and plated.
just replaced the s/c, still doing it.... going to try unplugging knock sensor after it cools down.
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Sun, 03 July 2005 06:25
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Hey Adsport, sorry for the delay in reply mate. Bummer, I thought it must have been the clutch slipping but if you have welded it up and it is still doing it, it can't be. If it isn't the supercharger itself it must be some kind of flow dynamic or pneumatic lock. How did it go with the knock sensor? Have you got a front mount or non factory intercooler? I am pretty keen to have a chat to you mate so give me a buzz when you get a minute or text me your phone number. I can be contacted on 0414559990 and my name is Glenn. I am sure that between us we should be able to nut this out. Has anyone got a factory workshop manual or PDF's of it? I know there is plenty of stuff around but I need all of it.
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Location:
Perth WA
Registered:
December 2003
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Re: Boost issues with 4AGZE
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Sun, 03 July 2005 10:30
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ok so ive done a lot of reading on the mr2oc.com and theres a 7 page thread there , i actually read it almost all of the guys there are having this caused by knock sensor signals, the ecu just cant handle the vibration.
the only way the guys in the US are getting around this is to fit aftermarket management so im heading there aswell (although i was going to go there eventually). before i do that, i have ordered a greddy knock sensor signal adaptor which im told might help somewhat, will keep you posted there.
i have a liberty water to air cooler setup on mine.
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Sun, 03 July 2005 23:02
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All you should have to do is remove the knock sensor from the block and wrap it in some plastic and cable tie it out of the way in the engine bay. Don't forget to leave it plugged in though. You could also bridge it with a resistor at the ECU end. I did this with my GTiR and never had any problems dropping maps after that.
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Location:
Newcastle
Registered:
July 2003
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Re: Boost issues with 4AGZE
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Sun, 03 July 2005 23:31
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just a thought.. if the knock sensor is going nuts.. could it be becasue your enigne is knocking ? dare i say you *may* not wwant to just ignore this ?
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Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Mon, 04 July 2005 04:08
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| Irish wrote on Mon, 04 July 2005 09:02 |
All you should have to do is remove the knock sensor from the block and wrap it in some plastic and cable tie it out of the way in the engine bay. Don't forget to leave it plugged in though. You could also bridge it with a resistor at the ECU end. I did this with my GTiR and never had any problems dropping maps after that.
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This will most DEFINITELY NOT WORK with a post 09/89 4A-G*** series engine on factory ECU. It has been thoroughly tested with a scan tool on the serial data line from the ecu, and proven that knock control was WORSE with the knock sensor as listed above, inferring that the knock sensor input to the ECU is not only looking for knock, but is looking for a GOOD signal too.....
... hence your suggested solution will not work.
If you are talking about intake temps ABOVE 100degC, then its pretty damn fkn obvious that you are pinging the p00hole out of your GZE, and producing what you call "partial boost" because of the lower density of hot air.....
.... remember that high school science experiement where you heat up a metal can with the lid open, and then put the lid on? Well that's a basic example of the difference in intake pressures between say 30degC and ~90degC intake temps. THINK ABOUT IT.
I myself have a great deal of experience with knock control problems using an AE92 MAP gze ecu + greddy emanage with my 100kW turbo 4a-ge.
The theories were endless, but the most commonly accepted theory was that top end rattles are a VERY similar accoustic noise to knock... smallport 4ag* engines produce top end rattles at as little as 100,000kms. This combined with engine conditions pertaining to knock sends the knock control circuit spastic, and it retards timing to poo-land.
With a supercharger, it is MOST DEFINITELY going to produce lower boost due to the FIXED nature of a supercharger, and how it produced boost. The simplest explanation is that it multiplies intake air pressure... thus if intake air pressure is LOWER due to EXTREME HEAT - you have less boost. Am i not correct (looks around for someone with more of an idea than me).
With a turbo of course, this is difference because you have a wastegate - ie a variable boost control device which compares intake pressure to relative pressure (atmosphere) and opens/shuts a valve accordingly to control intake pressure to a set level. So it will still make the 10psi it normally makes (for example), it will just take longer to get there.
In the end, i gave up and decided that aftermarket engine control and a top end rebuild was the solution... but sold the turbo kit and car separately instead.
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Location:
Adelaide
Registered:
July 2002
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Location:
Newcastle
Registered:
July 2003
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Re: Boost issues with 4AGZE
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Mon, 04 July 2005 10:05
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it does seem odd that you would be having a significant drop in pressure between gears.. especially if the pulley is welded on and the ABV is removed. my thought would be along the lines that it pretty much wouldnt have any choice *but* to move a given quantity of air and hence a given boost level ?
even if the computer was detecting knocking wouldnt it be unable to really do much effecting the boost. given it no longer has control over the charger clutch couldnt it only retard the timing/ change the mixture ?
do you have an inlet temperature probe ? im quite interested in seeing how this pans out and im keen to do the same sc14 swap .
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Location:
Bundaberg, Qld.
Registered:
May 2002
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Re: Boost issues with 4AGZE
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Mon, 04 July 2005 11:17
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as much as i dont like the ABV, i would (and did) run it with a fixed pulley s/c.
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even if the computer was detecting knocking wouldnt it be unable to really do much effecting the boost. given it no longer has control over the charger clutch couldnt it only retard the timing/ change the mixture ?
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agreed, i cannot beleive/understand that the knock sensor will limit boost when it detects detonation. it's purpose as i understand it is to retard the timing when detonatoin is detected.
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I will give you the benefit of the doubt that you didn't mean to come across that way but you would get more people listening to you if you were a bit more polite.
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unfortunatly you might have to get used to it, most posts are/come across like this.
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Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Mon, 04 July 2005 12:11
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i am not trying to be condescending.... this is a discussion, and i have a different viewpoint based on my experiences and results from dyno testing/tuning, street driving etc.. along with the experience of a rather knowledgeable and electronically wise 4ag* guru. Most people call him Ant.
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Karl, I do not see how you can effect the knock sensor by taking it off the block. If it is insulated (resilient mounted)and left connected it should not effect the operation, and it will be detecting 0 noise.
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Say what you will about Ant's (and my) knock sensor theory, but until you get a scan tool and test it out you cannot eliminate it. Actually you wont need a scan tool... just pull the knock sensor out tonight and go for a drive!!! *NB: dont plan on going too far in a hurry :P*
theory based on multiple cases of 4age 20v's with unexplainable flat spots. Use of scan tools shows knock control, without an audible knock
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As for the resistor bridge option, if TRUST make a knock sensor signal adjuster then it is obvious that there is a way around the knock sensor using electronics. It may not be as simple as using a single resistor but it would not be much more. I am very dubious about it being the knock sensor anyway.
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Yes, electronics theoretically can solve the problem. THis is what Ant was going to work on in his spare time, but that's still in the future. The idea was to "attenuate" the frequencies upon which the ECU detected knock, and attempt to maintain the regular engine noise frequencies.... because the use of a simple resistor resulted in either no resultant change, or complete retarding of ignition timing. Not that simple, and a lot of effort. Toyota were just too smart for their own good.
FWIW - Ant took jasonp1977's old AE92 blacktop 20V for a spin with the scan tool plugged in. WIth normal driving on an engine that was otherwise considered "VERY healthy"... there was a fair bit of knock being detected by the ECU! But the timing wasnt retarded very much when it was detected.
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As for detonation, it is VERY easy to hear det with any 4ag and it is not happening with my car.
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i said the same about mine.... yet there was knock control alright  ... every so often you would hear a teeeeeeny weeeeny bit of knock, but hardly anything for the ECU to go as spastic as it used to!
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The fact that my car still runs after 3 months is a great indication that it is not.
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So did mine WIth some HARSH driving.
And for 12 months prior to that as an N/A 100kW 4A-GE.
Funny thing was, in both guises the engine showed very similar signs of knock control. **see dyno graphs below**
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Why clowns still compare turbo outlet (compressed air) temps with roots type supercharger outlet temps is beyond me. There is no comparison and the supercharger air will always be hotter. As for my outlet temps, I will soon data log it and confirm my suspicions. Toyota quote temps up to 250deg are possible.
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I am well aware of the outlet temps possible from roots style chargers! Once you get them to the higher extremeties of their efficency and operating range, the outlet temps go WAAAAY up there. I quoted this as being a more prevelant problem for you than what i would have experienced, since my intake temps would have been much lower than that....
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The fact that it does it in one gear and not in the next is a good indication that your hypothesis is completely incorrect.
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hmmm... true in a sense, but it does emphasise my knock control/ignition timing retard theory. WHen mine started retarding it would do it erratically, all over the place... and eventually all the time. Only solution was turn off car for a little bit, and start it again.... the ecu was then usually alright for a while.
My thoughts are that with the uber-retardo timing
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I have no intention to "give up" on my project and I have not had a failure yet.
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good!! dont give up!! that would be giving up!!  But i do suggest that an aftermarket ECU might be able to help with your problems. Get the car on a dyno or on the road with a scan tool reading serial data (btw - EXACTLY which ecu are you using?) and see what the ECu says it's doing... i'd be VERY interested to know
BTW - here are the dyno graphs for both non-turbo and turbo, of the same engine in the same car. Note the severe dips in power from around 5000-6000rpm on both?
non turbo setup was using 100kW ecu, turbo setup was using AE92 map gze ecu + greddy emanage (tuned by SAS who identified the problem, and tuned around it as best as possible)
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Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Mon, 04 July 2005 12:16
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feral - thanks for the confidence vote champ
im not saying that the ECU is able to control boost, but that as an indirect result of retarding the poo out of ignition timing, it might possibly be able to indirectly affect boost pressure..... maybe
at the end of the day, i wish you the best of luck in diagnosing the problem and fixing it difficult problems like this are NOT fun !
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Location:
Bundaberg, Qld.
Registered:
May 2002
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Re: Boost issues with 4AGZE
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Mon, 04 July 2005 13:59
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| THE WITZL wrote on Mon, 04 July 2005 22:16 |
im not saying that the ECU is able to control boost, but that as an indirect result of retarding the poo out of ignition timing, it might possibly be able to indirectly affect boost pressure..... maybe
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earlier on in the thread i think i read that the knock sensor could/might be limiting boost. something i doubt, but you never know.
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Location:
Perth WA
Registered:
December 2003
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Re: Boost issues with 4AGZE
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Mon, 04 July 2005 14:35
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possibly the understanding of what is happening in this situation cannot be fully understood by those who arent experiencing it in the entirety that Irish and I are. i have my SAFC-II monitoring airflow %, knock, rpm,TPS. i have a boost gauge setup (greddy) aswell. i think the only way that you guys are going to come close to experiencing this phoenomena is to see it for yourself so i will be going and taking some video and posting it for all to see.
the thing with it is basically this, when you drive you get up to a certain RPM (mine does it mostly after 4400) and you can increase throttle position or keep it the same , and boost pressure will decrease. AT THE SAME TIME that boost pressure is decreasing the airflow percentage is going down (directly related), usually goes down to around 34%, which is the same as what WOT at max revs are in n/a mode (no boost on 8.0:1 motor) which means that the airflow meter is actually closing because no air is being drawn through it.
i will be posting video of this with all meters setup after thursday/friday, stay tuned.
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I Supported Toymods
Location:
perth
Registered:
September 2002
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Re: Boost issues with 4AGZE
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Mon, 04 July 2005 16:40
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Hey guys, goddamn that must be driving you two crazy.
'Wagonboy' on toymods may have had the same problem and solved it!
Car
-Ae93 with ae92ze MAP, nevo pulley kit, front mount
Problem Description
-Random irratic power / boost drops
-Sometimes it would pull beautifully all the way to redline
-sounds exactly as 'Adsport' described it, i was in the car when it happend once, power was moving all over the place almost as if the engine was suddenly running at like 70% - 30% -50% etc
-generally happend at over 4000rpm
-he tried everything, even replaced crank angle sensor
Solution
-Replace ECU (with another standard ZE ecu)
-Turns out that coolant was leaking from the heater pipes behind the dash and dripping onto the ecu.
I know it sounds strange to 'Irish's' situation because all he did was upgrade SC... but hey fuck it... sounds like you guys have tried everything else, why not give it a quick try?
If one of you is in Perth you can try plugging my ae101ZE ECU in if you like.
Good Luck
-daniel-
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Mon, 04 July 2005 22:46
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Now you have realised just how crazy this problem is Toof. A slipping belt or clutch is the only mechanical thing I can think of that would cause the symptom of partial boost. Is there such a thing as compressor stall in a supercharger?
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Mon, 04 July 2005 22:59
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Adsport, I am going to try removing and remounting the det sensor but I am in the process of moving from Adelaide to Darwin and will be pretty busy for the next two weeks. I am pretty keen to hear how your stuff goes so keep me informed mate.
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Location:
Perth
Registered:
January 2005
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Tue, 05 July 2005 05:46
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Thanks Nick. I was thinking of how to triple confirm that the belt was not slipping. Timing marks, reed switch, I just can't see how you could 100% guarentee it is not slipping. Anyway, all help gratefully accepted.
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Tue, 05 July 2005 06:06
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Also Nick, from memory the supercharger rotors are fixed to the main shaft by a whopping great pin. I think it would be impossible for them to spin on the shaft. Can anyone confirm this?
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Location:
Perth
Registered:
January 2005
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Re: Boost issues with 4AGZE
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Tue, 05 July 2005 06:23
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Hi,
Checking for belt slippage is an easy conecpt, but not so easy to realise. Remember you are looking for SIGNIFICANT slippage.
One reeeeasonably o.k. method might be to put an appropriate magnet on the inner SC pulley. Buy a Hall-effect sensor (open collector type) set it up with a pullup resistor to battery voltage so it will output a 12v square wave then use a suitable (MOST ARE) tacho gauge, And watch if its reading suddenly drops when you loose you boost...
Regards, Nick
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Tue, 05 July 2005 06:26
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Yeah, I was thinking along those lines. I am in the middle of moving from Adelaide to Darwin this week so this is all going to have to wait a month or so. I am just glad that someone else out there knows what I am talking about.
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Location:
Perth WA
Registered:
December 2003
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Re: Boost issues with 4AGZE
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Tue, 05 July 2005 12:33
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bayka: i know wagonboy's car well , did his cooler piping and was side by side at $2.00+ on sat night trying to not let the bugger beat me hahah
Nick: belt slip,it seems the only logical thing to be honest,although a fair few people are experiencing the same thing but it seems to dissapear when changing to aftermarket ECU which is boggling... im rethinking the way that the belt runs, i think i can get at least 30% more contact on the s/c pulley by re routing the belt to run under the tensioner from the top instead of over it from the bottom, but thats also another R&D project. add to your list a supercharger swap aswell, as i thought i had a collapsed bearing or something causing irregular rootes clearances which would relate to irregular boosting.
great theory about hooking up the tacho setup onto the s/c nick youve always got that brain turned on! haha
is anyone here a machinist? cos id be keen for a gilmer belt drive hahaha
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Location:
Newcastle
Registered:
July 2003
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Re: Boost issues with 4AGZE
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Tue, 05 July 2005 13:06
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whilst whitzl's ecu based theories are well founded im thinking along the lines of...
if the crank is spinning at 5000rpm the charger is spinning at 7000rpm (stock charger pulley w/ nevo) now given it is a ~1400cc/rev charger it *should* be moving 1400cc of air per revolution of of the charger/... hence moving 5000L of air per min.. ?
now assuming there is nothing preventing the charger from moving the prescribed quality of air it *should* continue to make a given positive pressure. if you are measuring the flow from the AFM and it is actually dropping then *something* must be preventing the charger from delivering that air. be it a leak, the charger being unable to move the air, charger not spinning at the prescribed rpm..
i couldnt see the two rotors in the charger not spinning correctly else as mentioned above it would make a god awful racket.
i like the idea of checking that rpm the charger is spinning at. to me belt slip seems to be the most likley cause. tighten it up harder.. worst thing that will happen is the belt will snap. give it a shot jsut make sure you have a spare
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I Supported Toymods
Location:
perth
Registered:
September 2002
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Location:
Newcastle
Registered:
July 2003
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Re: Boost issues with 4AGZE
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Tue, 05 July 2005 22:28
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possible however if the engine was producing insufficent torque to continue the supercharger to spin given the are in a "locked" mechanical system. ie: 1crank revolution 1.4 supercharger revolution. for the supercharger to move less air wouldnt it have to spin slower... and if the belt was not slipping wouldnt the crank also have to significantly drop in rotational speed ?
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Wed, 06 July 2005 01:38
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There is another reason why the boost will not be consistent. If there is a flow dynamic (turbulence/restriction) being caused at a point in the system then it could cause back pressure in the post supercharger air tract. Much like when you have an exhaust restriction due to a poorly designed / mismatched exhaust. It will normally flow at low revs but may create so much turbulence in a partial boost condition to actually block airflow. It can happen based on flow and it can happen based on harmonics or even a combo of both and the end result is almost like a throttle.
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Location:
Perth WA
Registered:
December 2003
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Re: Boost issues with 4AGZE
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Wed, 06 July 2005 05:33
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im thinking today that its possible that due to the extra rotational mass of the upgraded supercharger size (mostly internally) the engine may not have enough torque to spin it at such revs and maybe the belt is slipping on the actual crank pulley. ive had a look at 1GGZE motors and 4agze motors to check out the layout of the belt and tensioner, trying to see if there is a different pattern and possibly that the 1GGZE has a better mechanical advantage with the belt and pulley setup that the belt is forced to grip, instead of prone to slipping.
if you look at this picture here, this is of a 1GGZE :
the engine rotates clockwise, and thus PULLS the belt through the tensioner.
on the 4AGZE, the tensioner is run from the bottom:
so here we can see that effectively the belt is being moreso pushed through the tensioner than pulled out of the pulley.
My theory is that maybe flex in the belt, which would cause the belt to slip, is giving slack from the force of being pushed by the crank to go over the tensioner pulley thus snowballing the effect. I would really like to try setting up the belt so that it is fed to the s/c first then over the top and under the tensioner, up to the water pump and then down back to the crank.
doe sit make any sense to anyone else?
this would also possibly give us more contact on the supercharger pulley and lessening the risk again (in theory) of a slipping belt.
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Location:
Newcastle
Registered:
July 2003
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Re: Boost issues with 4AGZE
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Thu, 07 July 2005 08:15
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short of physycally mounting the charger on the exhaust side i cant see how you would really get around it. you could move the tensioner to the other side of the belt but it would still be pushing the belt towards the charger.
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Location:
Adelaide
Registered:
July 2002
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Re: Boost issues with 4AGZE
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Fri, 08 July 2005 01:11
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Adsport, I can't believe how tuned in we are. I had the exact same relevation and will be trying out a theory today. I will get a (little) bigger drive belt and hopefully this will allow the tensioner to travel higher and force more contact onto the supercharger and crank pulley. I am almost certian that this is going to fix the problem. I cranked the tension on the s/c belt up and it has def got better. The weather is cooler though so it may be effecting something too. I will keep you informed.
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Registered:
May 2002
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Re: Boost issues with 4AGZE
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Fri, 08 July 2005 01:34
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| Quote: |
Possibry an intermitant sripping belt?
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Interesting, so it is most likely what I said to begin with. Looking at Adsports pic and info it would make sense. When my car was running the SC it ran two belts, one for the SC and one for the Alt and water pump. The way mine had been setup it got the maximum amount of belt in contact with the crank pulley and SC as possible (to prevent the slip!) the tensioner was setup to pull more belt around the pulleys on the SC and crank.
I assumed this is how you guys would have done it too, as a few other people back in the day did it like mine here in Canberra. I guess I should not make assumptions.
A pic of how mine was set up is below, it used a custom crank pulley and a spacer on the water pump pulley, the tensioner for the SC belt was custom as well. This setup worked well. I have no idea what problems the SC14 may pose with this setup, you guys would know though.
Cheers, good to see you guys are getting close to a solution.
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Location:
Newcastle
Registered:
July 2003
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Re: Boost issues with 4AGZE
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Fri, 08 July 2005 02:17
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just thought of this. what about removing the water pump from the belt system entierly and using and electric water pump / that way you would only have the charger on that belt. similar to ke38's idea but wouldnt require another bracket and mount for the tensioner.
the only probme i would see with running the water pump off the alternator/ac pulley would be that it would be off the maller crank pulley so you would require a smaller water pump pulley to spin it fast enough.
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Registered:
May 2002
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Re: Boost issues with 4AGZE
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Fri, 08 July 2005 02:39
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The electric water pump is a good idea to overcome some fabrication issues.
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the only probme i would see with running the water pump off the alternator/ac pulley would be that it would be off the maller crank pulley so you would require a smaller water pump pulley to spin it fast enough.
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Way back when this was done on my car this issue was considered, some research indicated that it was quite safe to "under-drive" the waterpump, this proved to be correct as the car never suffered any adverse temperatures under any load or rpm range in a variety of conditions (we get a wide temp range here). If you were concerned it would be quite easy to find another ribbed pulley for the water pump from another vehicle that is close to the diameter you require.
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Location:
Newcastle
Registered:
July 2003
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Re: Boost issues with 4AGZE
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Fri, 08 July 2005 02:50
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fair enough, in the aw11 engine bay id definantly want to be keeping enough air moving as it kets pretty hot being quite cramped. regardless an electric unit would certainly solve some fabrication and fitment issues.
it would also remove some of the load from the engine crank as well assuming the current alternator had sufficent capacity to drive it.
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Location:
Canberra
Registered:
May 2002
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Re: Boost issues with 4AGZE
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Fri, 08 July 2005 03:31
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I'm in the middle of converting my mr2 to an electric water pump setup (among many other things)
It's not a quick and easy change, you need to physically cut the old pump in half and weld up the nose, becuase the belt now cuts directly though where the front of the pump used to be. The thermocouple for the EWP is too big to fit through the cooling passages so, you need to do some weirdness there as well..
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Location:
Perth
Registered:
January 2005
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Re: Boost issues with 4AGZE
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Sat, 09 July 2005 14:02
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RE: electric water-pump
Are you REALLY sure you want one? Maybe the benefits don't outweigh the hassle. Still, with a ZE every HP counts...
You'll have to make an 'pump adapter' block up, and re-route some lines. (I also removed my thermostat - so I guess that complicated things quite a bit). Finding fittings for the piping was a pain! Radiator places quoted me $70/m for brass pipe..I ended up using copper for $23/m!
My first electric pump seized (plastic impeller 'welded' itself to plastic pump body), I still don't know why maybe to do with the pump sitting around for nearly three years before I installed it. My coolant ended up boiling a little, luckily I was very vilgilent about constantly checking everything since I installed my homebrew EFI...........
Nick.
PS: a couple of pics of the EWP installation are on my webpage - if you have a look around on :-
http://www.e-wire.net.au/~nrparker/MR2/NewEngine/n ew_engine.htm
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Location:
Bundaberg, Qld.
Registered:
May 2002
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Re: Boost issues with 4AGZE
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Sat, 09 July 2005 21:06
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| toof wrote on Thu, 07 July 2005 18:15 |
short of physycally mounting the charger on the exhaust side i cant see how you would really get around it.
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sort of like this...
 
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Location:
Perth WA
Registered:
December 2003
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Re: Boost issues with 4AGZE
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Sun, 10 July 2005 09:46
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cheers for hte pics feral , looks like a bit of pissing around.. coiuple of us here in perth are trying to hook up some ghetto gilmer drive setup at the moment , hoping it turns out ok..
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Location:
Bundaberg, Qld.
Registered:
May 2002
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